Work support



Aug. 28, 1928. 1,682,456

H. H. YERK ET AL WORK SUPPORT Filed March l2, 1925 6 Sheets-Sheet l Aug. 28, 1928.

1,682,456 H. H. YERK ET AL Filed March l2, v1925 6 Sheets-Sheet 2 INVENTORS #W7 /J` Lm far( f im TTORNEY Aug. 28, 1928,.

H. H. YERK ET AL WORK SUPPORT Filed March l2, 1925 6 Sheets-Sheet 3 6 Sheets-Sheet 4 WORK SUPPORT Tim 5.

H. H. YERK ET AL Filed March l2, 1925 Aug. 28,' 1928.

Aug. 2s, 192s. 1,682,456y

H. H. YERK E r AL WORK SUPPOR T Filed March 12, 192s" 6 sheets-sheet 5 Aug. 28, 1928.

H. H. YERK ET AL WORK SUPPORT Filed Marh 12, 1925 6 Sheets-Sheet .6

Patented Aug. 28, 1928i. i

UNITED STATES PATENT oF F l C E HENRY H. YERK AND WILLIA J.'BAUMBERGEIR, OF DAVENPORT', IOWA, ASSIGNORS T MICRO MACHINE COMPAl'Y, OF BETTENDORF,'IOWA., .A CORPORATION OF IOWA.

wonx surroar.

Application filed March 12, 1925. Serial No. 15,050.

This invention relates to machines for in; ternal grinding and boring, and more particularly to fixtures associated therewith for holding cylinder castings during the Wall finishing operations. i

In finishing the walls of cylinders, and the like, which are to be associated in use in longitudinal axial alignment either in pairs or in a plurality of parallel groups, it is recognized that due to the present methods of holding the work, large limits must be permitted for roundness and axial alignment, as Well as :for the parallel relation of the aligned groups when so associated. Such limits as noW are permitted are very undesirable because they eliminate the possibility of a close fit of the pistons and their rings with the bores, and this, together with the friction caused by mis-l alignment within the permitted limits, great? ly decreases the efficiency of the pump or other structures of which the cylinders form a part.

It is the present practice to finish the bore .of each cylinder while disassociated, and to then align and secure the cylinders in longitudinal relation in any number of groups which may be desired. The variance in the castings, and the inability to present each casting tothe finishing tool in the same axial relation, make it necessary to tolerate the present large limits. AIt will be readily seen that the operation necessary. to secure each casting separately to a fixture in a similar relation, and the assembly of the same after the finishing operations are completed, cause 'a great deal of time to be consumed, and this is also true when suchv a device must be disassembled and assembled, respectively, before and v after refinishing operations.

One of the objects of our invention is to provide a fixture for holding one or more associated pairs of longitudinally extending cylinders, Which can be adjusted to present the outer end of each cylinder endwise to a finishing'tool in a manner such that the bores of the finished walls of each pair of cylinders will be round, and relatively in accurate axial longitudinal alignment.

Another object of our invention is to provide/a fixture for holding associated, longitudinally aligned cylinders arranged in parallel pairs, which can be adjusted to present the outer end of each cylinderendwise to a finishing tool in a manner such that the finished Walls of the cylinders of each pair will be round and with the bores of each pair accurately axially aligned and in parallel relation relative to each other.

l Still another object of our invention is to provide a fixture upon which one or more pairs of aligned cylinders can be secured in assembled relation during all of the operations necessary to finish the interior Wall of each cylinder, the fixture being adjustable to present the outer end of each cylinder to a finishing tool, so that the finished interior Walls of each pair of cylinders will be round and the axes of the bores in accurate longitudinal alignment.

A further object of our invention resides m mechanism which is associated with a rotating tool moving in an orbital ath to accurately indicate when the cylin ers are held so that the axes of their bores will be presented in the same axial relation to the tool for the finishing operation. f

Still another object of our invention resides in the method of finishing cylinders so that I their bores will be round and can be-associated in accurate axial alignment.

These and other itself will be better understood from a perusal of the following detailed specification. i'

In the accompanying drawings,

Figure 1 is a side elevation of a grinding machine With which an embodiment of our invention is incorporated.

Fig. lA is a perspective view of the structure shown in Fig. l, the work being shown in full lines.

Fig. 2 is an end elevation of the same.

Fig. 3 is a plan view of the fixture forming the subject of our invention.

Fig. 4 is a side elevation of the fixture turned on end. c

Fig. 5 is an end elevation of the frame and platform sections of the fixture.

Fig. 6 is a transverse section of the fixture taken on line 6-6 of F ig. 3

Fig. 7 is a transverse section of the fixture taken on'line 7 7 of Fig. 3.

Fig. 8 is a' horizontal sectional view of the fixture taken on line 8-8 of Fig. 7 showing objects and the invention' the Work supporting bed removed from the fixture and the elevating mechanism.

Fig. 9 is a plan view of the rotatable base removed from the fixture.

Fig. 10 is an enlarged plan view of one end of the fixture with the indicator carrier post in section.

Fig. 1l is a perspective view'of the platupon the machine so that form and the adjustable support therefor with the mechanism for raising and lowering the work carrying platform.

Referring now to the drawings by characters of reference. 10 represents the frame of an internal grinding or boring machine, which is provided with a reciprocable carrier bed 11 for advancing work to andfrom a rotating tool, the longitudinal axis of which extends in the same direction as the movement of the bed. For purposes of illustration, we have shown a grinding wheel 12 secured to a spindle 13, which is mounted in the head stock 14 of the machine, and itwill be understood that the spindle is driven to rotate upon its own axis and to also rotate at a slower speed bodily in an orbital path which is ec centric to the axis of the spindle. The mechanism for rotating the tool in such manner, and for reciprocating the bed, are carried by the machine frame and may be of` any conventional construction, but preferably is of the type shown and described in our pending application, Serial No. 730,626, filed August 7, 1924. f

)Ve provide an improved fixture upon which work, such as a plurality of aligned cylinder castings, can be secured and moved into positions to be operated upon separately by the tool without further adjustment of the work on the fixture after once set in proper position. This result is obtained by making the fixture in a plurality of sections which are relatively,- adjustable and mounting it it can be adjusted present the outer end of any cylinder to to the tool. The fixture includes generally, a pivotally mounted base member 15, a frame 16 mounted upon the base and slidable in a horizontal plane thereupon, a platform 17 upon which work is secured, and mechanism mounted upon the frame for supporting the platform and adjusting the elevation thereof.

The base is in the form of a plate which is provided with an aperture 18 (Figs. 7 and 9) extending vertically through the central portion thereof to provide a bearing for a vertically extending pivot pin 19. The pin 19 is carried in a bearing 2O seated in a recess in the top of the reciprocating table or carrier member 11. The upper portion of the base4 adjacent the aperture 18 is formed as a boss 21 to provide a seat for the frame shifting mechanism, and to also reinforce the base adjacent the aperture. The edges of the base are4 provided with inwardly extending aligned slots 22, which can be engaged by a latch 23 (Fig. 1) carried by the longitudinally reciprocating table to prevent rotation of the base, and cause it to travel rigidly therewith. The top wall of the base is pro- V vided with a pair of parallel spaced ribs 24 pf the aperture 18.

which project vertically therefrom and extend transversely across the base on each slde The top Walls of these ribs are fiat and lie in the same horizontal plane, while the outer sides thereof are slop ing to provide dovetailed hearing surfaces. The bottom of the base rests upon the reciproeating carrier 11 and, as explained, can be rotated in a horizontal plane thereupon, or can be locked so that it will reciprocate in a set position with the table.

The frame 16 is carried upon the ribs 24 of the base member 15 and is adjustable thereon across the path ofthe grinding wheel. The bottom of the frame is undercut transversely to provide a. dovetail seat 25 which fits over and rides upon The wall 26 forming one side of the dovetail is parallel with the side walls of the ribs, while the other side 27 extends longitudinally at an angle. The front end of the dovetail seat is wider than the distance between the sides of the ribs and a gib 28 is inserted in the space between the wall 27 and side of the adjacent rib, when the frame and base are assembled. By means of the gib screw 29, the gib may be adjusted inwardly to take up wear. The `gib, however, is not tightened sufficiently to prevent transverse movement of the frame 16 upon the ribs 24 of the base member, which movement is effected by the means about to be described.

An internally threaded nut 3() is secured upon the upper surface of the boss 21 on the base by screws 31, and a screw shaft 32 ex tends through the nut, meshing with the threaded interior thereof. The shaft and nut extend transversely of the base 15 and intermediate the sides of the dovetail scat portion 75. The frame 16 is provided with aligned apertured housings 33, one of which is formed at one side of the frame while the other is affixed to the opposite side of tbe frame, and the unthreaded ends 34 of the shaft are rotatably mounted therein, with their ends projecting beyond each side of the frame. Suit able bearing members 35 are provided within the formed supporting housing for the shaft, and thrust bearings 36 are provided for the shaft at the inner end of the housings, which are also associated to prevent longitudinal displacement of the shaft. Suitable hand cranks 37 are secured to each end of the shaft, and it will be seen that the frame will be moved horizontally upon the base by turning either of the cranks. A micrometer dial 38 is secured to each of the outer ends of the shaft ends 34, and may be set so that the operator can determine from their position the exact horizontal relation that the frame is in with respect to either the base or the table.

Mechanism is carried by the frame 16 for supporting the platform 17, and is arranged so that the platform can be adjusted bodily in a vertical plane. A pair of crank shafts 39 (Figs. 6 and 11) extend transversely in parallel relation, adjacent the ends of the frame. The top wall of the frame, is pro the ribs of the base member.

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of the shafts rotated. The f crank shafts extend the front of the vided with pairs of upstanding Abosses lwhich serve as the lower portion of a bearing for carrying the shafts. Bearing caps 41 are secured by bolts 42 to such bosses and thus provide bearings in which the shafts can be rame is provided with apertures 43, intermediate each pair of bosses, through which the crankportions 44 of the shafts can rot-ate. The front ends of the into longitudinally di- 45, which are secured to frame by bolts. A driving shaft 47 extends longitudinally Aacross the front end of the frame and is mounted in the housing members 45. ormgears .48 are secured by keys to the driving shaft and are enclosed by the housings 45. The threads of the worm gears are arranged to run in opposite directions for purposes hereinafter described, and gears 49 are secured to the ends 39 within the housings and are arranged to mesh with the worm gears 48. One of the housings is provided with an extended bracket housing 50 which projects beyond the end of the frame and carries an end of the driving shaft 47. A bracket 51 is secured to the opposite side of the frame, and

vided housings a shaft 52 extends transversely across the side.

of the frame and is rotatably mounted in the bracket and bracket housing. A worm gear 53 is secured upon the driving shaft within the bracket housing 50 and is arranged vto mesh with a worm gear 54 secured to the shaft 52. Each end of the shaft 52 is adapted to receive a hand-crank 55, by means of which the associated mechanism can be manually operated to raise and lower the platform. When the shaft 52 is rotated it will rotate the shaft 47 through the gears 53 and 54, and the shaft 47 will rotate the crank shafts 39 in unison, and in opposite directions, through means of the associated gears 48 and 49. The crank portions of the shafts will in this manner be rotated, and will bodily elevate or lower the platform which is attached thereto.

The platform 17, which is located in a plane above the frame, is provided with a flat upper surface forcarrying work, which in this instance is illustrated (Figs. l and 2) asa plurality of associated pairs of aligned cylinder castings arranged in parallel pairs respectivel in longitudinal alignment. The under si e of the platform is provided at opposite sides with parallel and similar grooves 56, the walls of which slant in opposite directions and are parallel with respect to each other. Two pairs of grooves 56 and are provided with dovetailed heads 59 (Figs. 6 and 11). The adjacent faces of the heads in each groove bear against the inner wall of the groove and are secured thereagainst by wedge members 60 which engage the outer wall of the grooves 56 and of the dovetail heads.

supporting members 58 v (Fig. 11) are adjustably positioned in the b Bolts 6l extend ver-- `tic-ally through the wedge members .60 toad-y ]ustably secure them to the platform. .When the wedge members 60 are properly secured in place, there will be no movement of the platform 17 transversely relative to the frame 16, but the heads 59 of the supports 58 may have a limited movement along the grooves 56 lwhen the crank shafts 39 are operated to elevate or lower the platform 17, as will be more clearly understood from an inspection of Fig. l1. The lower end of the supporting members 58 provide bearings 62 through which the crank portions 44 of the shafts 39 extend. It will thus be seen that the platform is supported on and connected to the frame by the crank shafts which are rotatably mounted in the bearing portions of the supporting members. The members 58 are located and arranged to support` the platform at all times so that it will extend in a horizontal plane, and the throw of the crank arms is in opposite directions so that bodily movement vertically of the platform will be uniform and there will be no binding suc-h as might be caused if `the components of the lifting forces tending to tilt the table were not counterbalanced. The rotation of the elevating v mechanism will, therefore, cause the platform to move bodily in a vertical plane.` The upper side of the platform 17 is provided with grooves 57 for the adjacent surfaces of the platform and the frame. to prevent lateral displacement of the one with respect to the'other in all vertical movement. This comprises a pair of pins 64, (Figs. 5 and '8), which are secured on opposite sides and adjacent the ends of the frame and extend vertically above the top surface thereof. A pair of recessed bosses 65 are car'- ried by the under side of the platform in a position to align with the pins when the platform is assembled upon the frame. The pins are arranged to telescope vertically within the bosses and are of sufficient length to remain therein at the topmost vertical position in which the platform can be elevated. Suitable cover plates 65 may be set into the top ofthe platform to close the upper` ends of the bosses, if desired. It will thus be seen that we have'provided mechanism to prevent any lateral play between the platform andA the frame.

Indexing mechanism is associated with the end of the machine, by which the operator can present the work held by the platform to the grindin tool with delinite accuracy. A racket ase 70 (Fig. 10) is secured to the. end of the reci rocating table 1l by bolts-71, and a standar 71 (Figs. 2 and 10) extends up wardly therefrom in avertical direction. The upper end of the standard terminates in a split head 72, which forms a longitudinally extending bearing for a rotatable shaft 7 3. A screw 74 extends through the upper split porian tions of the holder and serves to clamp the shaft against displacement in the bearing.

An indicator arm extends through a transversely formed slot in the shaft 73 and terminates at one end in a longitudinally extending pointer. A set screw 76 is screwed into the end of the shaft to engage the indicator arm for maintaining the pointer end in the desired position to describe a circle of desired radius. It will be understood that the standard is secured to the base in such position that the shaft 73 carried thereby will lie in exact axial longitudinal alignment with the axis of the orbital movement of the spindle carrying the grindingr wheel 12.

The worlf. is placed upon the platform and is first adjusted so that the axis of the orbital rotation of the grinding wheel coincides with the longitudinal axis of the bore of the cylinder adjacent thereto.- The indicator arm is then adjusted upon its shaft so that the pointer will describe a circle corresponding to the bore at the outer end of the cylinder in alignment with the cylinder adjacent the grinding wheel. Such cylinder is then adjusted until the pointer of the indicator, when. revolved, coincides with the circle of its bore. As the axis of rotation of the indicator aligns with that of the orbital movement of the grinding wheel, the operator can then secure the work upon the platform with the knowledge that the axis of the bores of the aligned cylinders will be nished in accurate longitudinal alignment.

A bracket 77 is secured to the end of the base 70 and apertured bearing ears 78 (Figs. 2 and 10) extend therefrom for receiving a pintle pin 7 9. The standard 71 is hollow and the lower end thereof is provided with bearings 80 which lie intermediate the ears 78 and through which the pintle pin 79 extends. With this form of pivotal mounting, the indicator carrying standing can readily be swung downwardly to remove it froln the path of the fixture during rotative adjustment thereof.

The end portion of the reciprocating carrier 11 is provided with a recess 81 (Fig. 1), within which a block 82 is seated and secured. The upper surface of the block is flush with the upper surface of the carrier, and a passage 83 extends longitudinally through the block and vertically through the upper surface at the forward end thereof. The latch 22, heretofore referred to, extends through the passage and across the bracket 70. The bracket is provided with a flanged end 84 having an aperture into which the extended end of the latch is slidably mounted. The forward end of the latch is provided with a keeper which extends vertically in the open end of the passage to limit the horizontal movement of the latch. A coil spring 85 is secured at one end to the extended portion of the latch, and bears against the flange 84 of the bracket at its other end, suiiicient tension being thereby provided upon the latch to normally project it in a forward position where it will enter either of the slots 22 in the base when positioned to ali n therewith. A lever 86 (F ig. 1) extends rom beneath the indicator standard and is pivoted at 87 to the bracket base. The inner end of the lever is pivotally connected to the latch extension at 88, and the latch can be moved out of engagement in the slots in the base by swinging such lever.

The work, which is illustrated secured upon the platform to, show some of the operations which can be made with our invention, consists of a plurality of cylinder castings assembled to constitute a railway pump casing. The diametrically opposite cylinders 90 and 91 are of the same dimensions, and are larger than the diametrically opposite cylinders 92 and 93. The cylinders are associated in longitudinally aligned parallel pairs, each pair consisting of a large and small cylinder, and a connecting partition member 94 is bolted intermediate the aligned pairs of cylinders. Vith our fixture each cylinder, after being properly secured on the platform, can be linished without further adjustment thereof with respect to the platform, and the finished interior walls will be round and the bores therein will be accurate in size, and the axes of the interior walls of each pair of c linders will be in accurate longitudinal alignment and parallel with respect to the other pair.

The work is clamped u on the platform, after being positioned as above described, by suitable clamps 95 which are adjustable in the grooves 57. In positioning the work, the fixture may need to be adjusted vertically or transversel in a horizontal plane, as heretofore descri ed, so that the tool caribe placed with the axis of its orbital movement coinciding with the axis of the c linder bore. The machine is then ready to e put into operation. When this is done the bed 11 is reciprocated to carry the cylinder endwise toward the. grinding wheel, and the wheel will ro tate about its own axis and also bodily in an orbital path at a slower speed in conventional manner. When this cylinder has been iin-` ished, the latch 23 is removed from the notch 22, and the base carrying the fixture is swung around upon its pivot 180, so that the latch can engage the other notch 22 therein. The work is thus swung in a horizontal plane, and

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if the work has been arranged so that the pivot 19 is centrally on a diametrical line between the cylinders 90 and 91, no further adjustment of the fixture will be necessary, and the cylinder 91 will be in position to be operated upon. If the work was not so positioned, the base can be adjusted horizontally to a position where the axis of the cylinder bore aligns with the orbital axis of the tool. The machine is operated to finish the bore, and the and a great deal of time in the finishin v horizontal plane.

tool is changed to finish the smaller bores of the cylinders 92 and 93. The fixture is then adjusted horizontally by moving the frame upon the base to a position where the 'axis of one of the bores ofthe smaller `cylinder ax ially aligns with the orbital axis of the tool, the machine can then be operated to finish such bore, provided the axial lines of the smaller and larger bores lie in the same If they do not, the platform can be raised or lowered, as the case may be, by the gearing and shafts described to secure the alignment of the bore with the orbital axis of the tool. After the smaller cylinder 92 has been ground, the fixture is rotated'upon the pivot 19 to its original position, and, if necessary, horizontal adjustment of the frame can be made to axially align this bore with the orbital axis of the tool.

' e original aligning of the axes of the res of one pair of the cylinders, by means of the indicating mechanism, will insure that the tool will grind the interior walls so that the axes of their bores will align axially, and so that the axes of the bores in each pair of aligned cylinders will be parallel with those of the other pair. It will be seen that when the casing assembly is once fixed in placeA allhof the cylinders can be on the platform,

Vchanging its position upon finished without the platform4 It will be seen that this method will save operations which .arenow consumed by t e present methodsQin which each casting must be sitio'ned and secured and removed from a ture.

It will also be seen that the bores of the pairs of cylinders will be groundso that they accurately align axially, and will be parallel, which is impossible when each casting is ground after being secured separately 4upon a fixture or upon different fixtures, and

then assembled in either parallel or longitudinal relation. The micrometer mechanism incorporated with the elevating and horizontal adjustment mechanism will indicate the exact location ofthe sections of the fixture relatively, so that under any circumstances the operator can place the work upon the platform with a positive knowledge of its location with reference to any adjustment which can be made.

Furthermore, it-is to be understood that the particular forms of apparatus shown and described, and the particular procedure Set forth, are presented for purposes of explanation and illustration and that various modifications of said apparatus and procedure can be made without departing from our invention as defined in the appended claims.

Vhat we claim is:

1. The combination chine having a table movement, a grinding with a grinding mafixed against vertical Wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinally of said spindle, of means fordisposing a cylinder in cooperative relation to said grmding Wheel spindle comprising a platform supported on said table and arranged to carry said cylinder, means for rotatin said platform, and means for moving sai platform vertically and maintain said platform in desired vertical position during a grinding operation, whereby to dispose said cylinder in desired relation to said spindle.

2. The combination with chine having a table fixed against vertical movement, a grinding Wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinall of said spindle, of means for disposing a cy inder in cooperative relation to said grindlng wheel spindle comprising a platform supported on said table and arranged to carry said cylinder, means for rotating said platform, means for moving said platform vertically and maintain said platform in desired vertical posit-ion during a grinding operatiom and means for moving said platfbrm in a horizontal plane transversely of said grinding wheel spindle, whereby said cylinder may be accuratel disposed in desired relation to said spin le.

3. The combination with a grinding machine having a table fixed against vertical movement, a grinding wheel spindle rotatable about its own axisand in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinally of said spindle, of means for disposing a cylinder in cooperative relation to said grinding wheel spindle comprising a base rotatably mounted on said table and securable in a desired position of rotatable adjustment, a frame carried by saidbase movable in a horizontal plane transversely of said grinding wheel spindle, a platform supported by Said frame and arranged to carry said cylinder, and means carried by said frame to move said platform vertically and maintain said platform in desired vertical position during a grinding o eration, whereby to dispose said cylinder 1n a grinding `mathe desired position with respect to said spinvd form su ported by said frame,

spindle comprising a base i'otatably mounted on said table, means to lock said base against rotation at a desired position of said base, a frame carried by said base movable in a horizontal plane, a platform supported by said frame and arranged to carry said cylinder, and means carried by said frame to move said platform vertically and maintain said platform in desired vertical position during a grinding o eration, whereby to dispose said cylinder in t e desired position with respect to said spindle.

5. The combination with a grinding machine having a table, a grinding wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinally of said spindle, of means for disposing a cylinder in cooperative relation to said grinding wheel spindle comprising a base rotatably mounted on said table, a frame carried by said base movable in a horizontal plane transversely of said grinding wheel spindle, a platcrank shafts carried y said frame to move said platform vertically, and means t0 indicate the vertical elevation of said platform whereby said cylinder may be disposed on said platform in desired osition with respect to said spindle.

6. 'ghe combination with a grinding machine having a table, a grinding wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinally of said spindle, of means for disposing a cylinder in cooperative relation to said grinding wheel spindle comprising a base rotatably mounted on said table, a frame carried by said base movable in a horizontal plane transversely of said grinding wheel spindle, a platform supported by said frame and arranged to carry said cylinder, means carried by said frame to move said platform vertically, means adjacent the portion of the platform more remote from the spindle for indicating when the cylinder is in position for grinding, said means comprising a standard secured to said table having a caring in longitudinal alignment with the axis of the orbital movement of said spindle, a shaft revolvable in said bearing, and an indicator arm adjustable transversely of said shaft.

7. The method of grinding the interior walls of an assembled casing containing two parallel airs of longitudinall aligned cylinders in w iich casing the cylin ers of each pair have different diameters and the diagonally o posed cylinders have substantially the same diameter, by a grinding wheel disposed on a horizontal spindle rotatable on its own axis and about an axis eccentric to its own, which method comprises disposing said casing adjacent said grinding wheel with the axis of one pair of cylinders in longitudinal alignment with the axis of said grinding wheel spindle and with the axes of all the cylinders in the same horizontal plane as the grinding wheel spindle axis, disposing one of the aligned pairs of cylinders directly adjacent said grinding wheel, grinding said cylinder, rotating said casing 180 in a horizontal plane to dispose the diagonally opposed cylinder of the same diameter in alignment with said spindle, grinding the walls of said diagonally opposed cylinder, disposing one of the remaining unground cylinders with its axis in longitudinal alignment with the axis of said spindle, grinding the walls of said cylinder, rotating the casing through 180 in a horizontal plane, and grinding the walls of the last remaining cylinder.

8. The combination with a grinding machine having a table, a grinding wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, and means for causing relative reciprocation between said table and spindle longitudinall of said s indle, of means for disposing worli in desire cooperative relation to said grinding wheel spindle, comprising a base rotatably mounted on said table, a frame carried by said base movable in a horizontal plane transversely of said grinding wheel spindle, a platform supported by said frame, and crank shafts carried by said frame to move said platform vertically.

9. In a grinding machine, in combination, a grinding wheel spindle rotatable about its own axis and in an orbital path about an axis eccentric to its own, an indicating device permanently associated with said grinding machine having an indicatin member adjustable about an axis disposed in exact longitudinal alignment with the axis of orbital movement of said grinding wheel spindle, a work supporting table intermediate said grindin wheel spindle and said indicating device, an means for adjustin work disposed on said work supportingbta le whereby portions of said work may e disposed in exact longitudinal alignment with said axis of orbital movement of the grinding wheel spindle.

lO. The combination with a grinding machine having a table fixed against vertical movement, a 'nding wheel spindle and means for causing relative reciprocation between said table and spindle lcngitudinall of said spindle, of means for disposing wor in desired position relative to said grinding wheel spindle, comprising a base su ported on said table, a platform sup orted by said base, and a member dispose intermediate said table and base, said platform being adjustable relative to said intermediate member, said intermediate member being adjustable relative to said base, said base being adjustable relative to said table, one of said adjustments permitting said platform to be ad- IIC justed vertically of the grindingv Wheel sired common longitudinal axis of the surspindle another of said adjustments permitfaces to be ground in longitudinal alignment ting said platform to be rotatably adjusted to with a horizontal axis of the grinding ma- 20 predetermined desired rotative positions, a chine, rotating a grinding wheel about itsthird adjustment permitting said platform to kown axis and simultaneously in .an orbital be adjusted vertically, and means for retainpath about said grinding machine horizontal J ing said platform in an desired vertical posi-v axis, causingv relative longitudinal move'- tion during the grinding operation. ment between said grinding Wheel and said 25 11. The method of grinding the interior casing whereby to grind the cylinder adja- Walls of a casing containing a pair of longicent the grinding Wheel, bodily swinging the tudinally disposed c linders to obtain longisupport and easing in a horizontal plane, and tudinally aligned cy indrical surfaces having grinding the other cylinder.

a a desired common longitudinal axis, which In testimony whereof, We hereunto aix our 3 comprises disposing said casing on a support signatures.

adjacent a grinding wheel, bodily adjusting said support and casing longitudinally and HENRY H. YERK.

laterally to dispose said cylinders with a de- WILLIAM J BAUMBERGER. 

